(a) Field
The invention relates to an electrowetting device.
(b) Description of the Related Art
Displays visually expressing electrical information signals have been quickly developed according to advances of the information age. In response to this trend, various flat panel displays having excellent characteristics such as thinness, light weight, and low power consumption have been quickly developed and have thus replaced the existing cathode ray tube (“CRT”).
As examples of the flat panel displays, there are a liquid crystal display (“LCD”), a plasma display panel (“PDP”), a field emission display (“FED”), an electroluminescent display (“ELD”) device, and an electrowetting display (“EWD”) device.
Among the flat panel displays, the EWD device visually expresses an information signal by using an electrowetting phenomenon. Here, the electrowetting phenomenon is a phenomenon in which interfacial tension of a fluid in an electric field is changed and the fluid migrates or is deformed. In the EWD device, a hydrophilic liquid and a hydrophobic liquid are inserted inside a pixel, and interface tension of the hydrophilic liquid is changed by the electric field formed by a voltage applied from outside the pixel to move the hydrophobic liquid, thereby displaying an image. The EWD device has advantageous characteristics of small size, low power consumption, fast response speed, and high color brightness, thereby being spotlighted as one flat panel display of the next generation.
To control transmittance of light and to increase a contrast ratio of light and shapes, a material of the hydrophobic liquid of the EWD device must have high optical density.